Human skin can be damaged by solar rays. Overexposure to sun can cause simple sunburn or erythema, along with burns of varying severity. Additional unwanted effects of overexposure to solar radiation include tanning, age spots, immune system suppression, photo-sensitivity and photo allergies. Sun exposure can cause the skin to lose elasticity and form wrinkles, yielding prematurely aged skin. In extreme cases, skin cancer is associated with long-term overexposure to solar radiation.
It has been estimated that the majority of sun related damage to the skin over a lifetime is the result of outdoor exposure to the sun's ultraviolet rays. The wavelengths relevant to sun related damage include the UV-A, UV-B and UV-C regions. UV-C region is at the shortest wavelength (100-280 nm) with the highest energy content, yet very little of UV-C rays pass through the atmosphere to reach the surface of the Earth. The UV-C rays along with the UV-B rays (280-320 nm) indirectly cause sun tanning and are most likely the source of skin cancers. The longer-wavelength (320-400 nm) UV-A rays directly cause sun tanning, collagen damage and other harmful effects. It should be noted that ˜98% of the sun's rays that reach the earth are UV-A rays. Commercially available sunscreen compositions offer a solution to the harmful effects of over-exposure to these ultraviolet rays. However, due to changing atmospheric conditions, increasing number of skin cancer incidents, and increasing awareness of the problem, there is a continuous need of new sunscreen formulations. Especially, there is an increasing need for sunscreen compositions with natural ingredients.
Topical application of sunscreen formulations is well known in the art. Sunscreen active ingredients are generally classified as organic or inorganic. Organic sunscreen agents absorb strongly over a range of UV wavelengths but are transparent to visible light. Some organic active ingredients of sunscreens (Oxybenzone, for example) are known to cause photo-allergic reactions, while others are suspected as estrogen disrupters. Inorganic sunscreen agents such as zinc oxide or titanium dioxide at higher levels leave visible residue referred to as whitening of the skin. Allergic reactions to zinc oxide and titanium dioxide are also known. These sunscreen active ingredients may also enhance the production of reactive oxygen species in the skin, which can produce skin damage.
To overcome these undesirable side effects of organic and inorganic sunscreen agents, there is a need for new formulations that can protect the skin from the harmful effects of ultraviolet radiation without any undesirable side effects.
Certain natural ingredients are known to have sunscreen activities.
U.S. Pat. No. 6,440,402 discloses a synergistic effect of Kaempferia galanga (ginger) root extract in sunscreen formulation. The patent also discloses a method comprising the introduction of an amount of extract of Kaempferia galanga into a composition sufficient to enhance the photostability of other sunscreen ingredients.
U.S. Pat. No. 8,337,820 and U.S. Pat. No. 8,216,55 both disclose formulation for protecting skin from UV-radiation, where the main ingredients of the composition are titanium dioxide and 5-hydroxy-tryptophan in the form of Griffonia simplicifolia-extract. In this preparation Griffonia simplicifolia extract is at least partially added due to its brown color to blend the white color of titanium dioxide.
In the art of sun protecting compositions, also compositions containing extracts of green tea, Aloe vera, calendula, chamomile and rosemary are known.
Additionally there are various disclosures where general skin care compositions include one or more plant extracts.
U.S. Pat. No. 7,731,942 discloses sun-protecting products containing caffeine, algal extracts, pineapple extract and other ingredients.
U.S. Pat. No. 6,524,599 discloses a composition for skin, nail and hair care where the composition contains milk thistle (Silibum marianum) with soybean protein and alpha tocopherol.
U.S. Pat. No. 5,876,736 discloses a skin care composition for revitalizing the skin and comprising plant polysaccharides among various other ingredients.
US patent application 2004/0096418 discloses a composition to lighten the skin color and comprising various plant extracts, including extract from common yarrow (Achillea millefolium).
US Patent Application number 2011/0229538 discloses a total skin care composition containing a combination of ascorbic acid and herbal extracts. It should be noted that the herbal extracts and nutrients are not specifically stated to function in the composition as a sunscreen, sunscreen enhancer or sunscreen booster activity. The herbal extracts include red clover extract, ginseng and St John's wort among other extracts.
Furthermore, there are disclosed compositions for different kinds of medical conditions where plant extracts and plant based ingredients are included.
For example European Patent publication EP1301194 discloses treatment of cancerous condition with essential oils including oil of Ravensara aromatica. 
European Patent publication EP 0952839 discloses a composition to treat burns, where the composition comprises St John's wort, and yarrow among other ingredients.
US application publication 2011/0212197 discloses a composition to treat viral conditions, where the compositions include yarrow extract.
U.S. Pat. No. 6,586,018 discloses a composition for treating premenopausal syndromes including red clover extract among other plant extracts.
Given the present background on sunscreens, the present invention has been created to enhance the effects of currently accepted methods for UV screening. The instant invention provides a sunscreen and sunscreen booster or enhancer comprising natural ingredients.